deny-soft-private-modifier

This plugin disallows the use of soft private modifier.

• ⭐️ This rule is included in Flat Config rdlabo.configs.recommended.
• ✒️ The --fix option on the command line can automatically fix some of the problems reported by this rule.

TypeScript's private modifier is only enforced at compile time. It can still be accessed at runtime through bracket notation or by casting to any. JavaScript hard-private fields (#) are runtime-enforced and cannot be bypassed from outside the class. This rule replaces private properties and methods with # fields and updates this.x references to this.#x.

Rule Details

This rule checks classes for the following patterns:

• A private property definition (private field = ...)
• A private method definition (private method() { ... })
• A this.field reference where field was declared as private

It does not report constructors, because private constructor() has a different meaning (preventing external instantiation). A private readonly property is reported; the fix removes private, adds #, and preserves readonly.

The rule auto-fixes by:

1. Removing the private keyword.
2. Inserting # before the property or method name.
3. Updating all this.field or this.method() references in the class to this.#field or this.#method().

Examples

Incorrect

class TokenStore {
  private token = '';

  private refresh() {
    this.token = 'new-token';
  }
}

Correct

class TokenStore {
  #token = '';

  #refresh() {
    this.#token = 'new-token';
  }
}

Options

This rule has no options.

When to enable

Enable this rule when a project wants runtime-enforced encapsulation for class internals. It is safe to run with --fix on existing code, but it changes public API surface: any code that was relying on compile-time private access at runtime will break.

See also

• @rdlabo/rules/restrict-try-block

Implementation

• Rule source
• Test source